1. Field of the Invention
The present invention relates to a power supply, a power management device applied to a power supply, and a method applied to a power management device, and particularly to a power supply, a power management device applied to a power supply, and a method applied to a power management device with both brown-out protection and overheat protection.
2. Description of the Prior Art
Many power products have a requirement for both brown-out protection and overheat protection. Because general power management integrated circuits (six-pin or high-voltage eight-pin series integrated circuits) are limited to an insufficient number of pins, and brown-out protection and a latch/auto-recovery function of overheat protection are not designed in to one power management integrated circuit simultaneously. Therefore, most common six-pin pulse width modulation integrated circuits only provide one pin for the latch/auto-recovery function, and a minority of power management integrated circuits only provide one pin for a single function (such as the brown-out protection).
The prior art executes the brown-out protection and the overheat protection separately, but detects the brown-out protection and the overheat protection simultaneously. When a voltage level of a pin of the brown-out protection is lower than a reference level corresponding to the brown-out protection, or a voltage level of a pin of the overheat protection is lower than a reference level corresponding to the overheat protection, a power management integrated circuit does not output pulse signals to an external switch again. Meanwhile, the power management integrated circuit is turned off to enter a sleep mode or a latch off mode. But, compared to the six-pin or the high-voltage eight-pin series power management integrated circuits, the power management integrated circuit has to include one additional pin. Therefore, the prior art can not execute the brown-out protection and the overheat protection simultaneously in the six-pin or the high voltage eight-pin series power management integrated circuits.